Exhibit 4.30

                            Milestone Scientific Inc.
                              220 S. Orange Avenue
                              Livingston, NJ 07039
                               TEL: (973) 535-2717
                               FAX: (973) 535-2829

                                December 28, 2001

Mr. K. Tucker Andersen
c/o Cumberland Associates LLC
1114 Avenue of the Americas
New York, NY 10036

            Re:   Milestone Scientific Inc ("Milestone")
                  Payment of Interest Under the Line of Credit Agreement

Dear Tucker:

      This will confirm that Milestone has agreed to issue to you and that you
have agreed to accept from Milestone 33,840 units in payment of all accrued
interest through December 31, 2001 under the Line of Credit Agreement between
you and Milestone, dated March 9, 2001. Each unit will consist of one share of
Milestone common stock and one warrant to purchase an additional share of such
common stock. The warrants will be exercisable at $.80 per share through January
31, 2003, thereafter at $1.00 per share through January 31, 2004, and thereafter
at $2.00 per share through January 31, 2007, at which time they will expire. The
warrants also will have antidilution protection against capital changes.

      Milestone will use its best efforts to file with the Securities and
Exchange Commission as soon as reasonably possible, but not later than June 30,
2002, a registration statement under the Securities Act of 1933, as amended (the
"Securities Act") on Form S-3, registering the reoffer, resale or other
disposition of the shares included in the units and the underlying the warrants
and will use its best efforts to cause the registration statement to become
effective as soon as possible after filing.

      By signing this letter, you confirm that (i) you are an "accredited
investor" within the meaning of Rule 215 of the Rules and Regulations under the
Securities Act, and (ii) you have acquired the units for investment and
acknowledge that the securities cannot be resold or otherwise disposed of until
they are registered under the Securities Act and any applicable state securities
laws or an exemption from registration is available.

      Since the securities will not be registered at the time of issuance, the
certificates representing the shares and warrants underlying the units delivered
to you will bear the following legends, respectively:
<PAGE>

      THE SHARES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN REGISTERED UNDER
      THE SECURITIES ACT OF 1933, AS AMENDED (THE "ACT"), AND MAY NOT BE SOLD,
      TRANSFERRED, HYPOTHECATED OR ASSIGNED EXCEPT PURSUANT TO AN EFFECTIVE
      REGISTRATION STATEMENT UNDER THE ACT OR IN A TRANSACTION WHICH IS EXEMPT
      FROM REGISTRATION UNDER THE ACT.

      NEITHER THIS WARRANT NOR THE SHARES OF COMMON STOCK WHICH MAY BE ACQUIRED
      UPON THE EXERCISE HEREOF, AS OF THE DATE OF ISSUANCE HEREOF, HAS BEEN
      REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE "ACT"), AND
      MAY NOT BE SOLD, TRANSFERRED, HYPOTHECATED OR ASSIGNED EXCEPT PURSUANT TO
      AN EFFECTIVE REGISTRATION STATEMENT UNDER THE ACT OR IN A TRANSACTION
      WHICH IS EXEMPT FROM REGISTRATION UNDER THE ACT.

            Please acknowledge your agreement and understanding of the above
provisions by signing and dating a copy of this letter and returning it to us by
facsimile and mail. The securities will be delivered to you promptly after
receipt of your acknowledgement.

                                          Sincerely,

                                          MILESTONE SCIENTIFIC INC.


                                          By: /s/ Leonard Osser
                                              ----------------------------------
                                              Leonard Osser, Chairman
                                               and Chief Executive Officer

ACCEPTED AND AGREED TO
THIS 28th DAY OF DECEMBER, 2001


By: /s/ K. Tucker Andersen
   -----------------------------
        K. Tucker Andersen


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